Lymphedema of the extremities is a disease that could be primary, such as congenital lymphedema, or secondary, such as following radical lymphnode disection of the axilla and/or groin as in treatment for cancer.
Secondary lymphedema presents itself in many variables and one of the forms of treatment is an outside compression in order to help remove from the limb the extra lymph fluid that may accumulate every day in the subcutaneous tissue.
Conservative treatment is utilized in the form of pneumatic massage, Ace bandages wrapping, arm elevation, etc. The apparatus here described is one that will produce a true gradient, from distal to proxymal pressure on the affected limb, that will help in reducing the amount of lymphedema, or edema, present in the subcutaneous tissue.
When the patient has a combination of lymphedema and edema, otherwise known as low concentration lymphedema, due to vascular obstruction, the problem is more complex and requires sustained pressure on the limb, for long periods, (thirty minutes to an hour) for better results. While Ace bandage wrapping provides this sustained pressure, it has the disadvantage of not being possible for self treatment, by the patient, and not having readily available a trained technician to do it for the patient as well as the fact that it results in uneven pressure and therefore does not produce very good results.
This apparatus substitutes the mechanical portion of the circulator for a series of electronically controlled valves, to produce the inflation of the respective compartment of the boot and to provide means for relief of this pressure or maintaining the pressure as desired. One prior art device employs a cylindrical sleeve, rather than a boot. The boot of the Applicant's invention will have a rigid sole with pressure applicable only over the dorsum of the foot, avoiding the above mentioned problems.
The prior art device is considered an open compression circuit, as long as the compressor is working as in its normal cycle, the pressure within the apparatus and the inflating will remain as selected, but it has no means to maintain the preselected pressure for any length of time, when this is required, as it occurs in many patients where the pressure must be maintained for thirty minutes to one hour; if the compressor was to be turned off at the end of the inflating cycle and before the deflating time, the pressure within the inflating device will be lost within the first one or two minutes, through the rotating cylinder.
When the above mentioned metallic rotating device is changed for an electronically controlled set of solonoid valves, the mechanical problem of rust, the uneven inflation and the lack of safety of use by the patient alone, are eliminated, adding separate manifolds that will maintain the air flow completely separate of the different compartments of the boots, and when one of said manifolds will contain a one way check valve and an electronically controlled solonoid valve for the release of pressure, the device will become a closed compression circuit and the pressure will be maintained for a longer time, or as long as desired, by not activating the release valve mentioned, or when the patient desires, will by choice through the use of a safety switch, selectively activate the release valve and release the compression, anywhere during the cycle.
The unnecessary pressures and strains placed on the foot and ankle are totally eliminated when a boot is utilized that provides the same shape of the leg and foot and a stiff sole is placed in the foot end, to produce support so that pressure is applied only to the dorsum of the foot and not a squeeze. The addition of a hip portion and means to hold it up at the waistline prevents the rolling down of the cylindrical sleeve that occurs on the cyclic inflation and deflation. This rolling down that occurs with the sleeve of the prior art device results in the formation of an unsupported roll where the lymphedema will accumulate, below the groin.
Additional safety features are: the addition of indicating lights that turn on and off with each individual line of inflation, to alert the patient of any fault in the mechanism of inflation. The selective device that the user has at hand to activate a relief valve for emptying inflated compartments, anytime during the cycle, so that if for any reason the user must get out of the boot, this may be accomplished without need of assistance.
All of these features make this new device useable by a person at home, without supervision, eliminating the need for hospitalization or travel to a clinic away from home.
The reasons that an inner boot of a single compartment is needed are two: First, since all of the materials utilized are thermal sealed plastics or rubber, they make a seam over which pressure is not applied, resulting in skin lymphatics taking pressure from above and below, to their damage. The inner boot will accomplish a smoothing of these areas eliminating the problem. An inflating device that consists of one single compartment has the physiological disadvantage to a user in that it produces equal pressure above, in the middle and at the lower end, all at the same time, contrary to the device with multiple compartments that produces a gradient pressure from distal to proxymal, assisting the normal flow of fluid and protecting the valves within the vessels themselves.